Imaging devices include cameras provided with an image shake correction device having a shake detection unit and a shake correction unit that corrects image shake caused by camera shake or the like. Such an image shake correction device detects angular shake using an angular velocimeter or the like and reduces image shake on an imaging plane by moving a part of a lens group serving as the shake correction unit or an image sensor.
However, there are cases in photographing performed at a close distance or photographing with high photographic magnifying power in which an image is affected by shake that cannot be detected only with an angular velocimeter. Consequently, image deterioration can arise due to image shake caused by so-called parallel shake that is applied in a direction parallel to the optical axis of a camera or a direction perpendicular thereto. For example, if macro photographing is performed when a camera approaches a subject up to about 20 cm, or if the focal length of an imaging optical system is long (for example, 400 mm) even when the subject is about 1 m away from the camera, it is necessary to actively detect and correct parallel shake.
Patent Literature 1 discloses a technology in which parallel shake is obtained from double integration of acceleration detected by an accelerometer and then a shake correction unit is driven using an output of a separately provided angular velocimeter along therewith. In this case, the output of the accelerometer is affected by an environmental change such as disturbing noise or a temperature change. Since such an instability factor further expands as acceleration undergoes double integration, highly accurate correction of parallel shake is difficult.
Patent Literature 2 discloses a method for obtaining parallel shake by deeming it as angular shake when the center of rotation is assumed to be at a position away from a camera. In this method, an angular velocimeter and an accelerometer are provided, a correction value and an angle are obtained using the rotation radius of the angular shake from outputs of the meters and accordingly shake is corrected, and the center of rotation can be obtained limited to a frequency band in which influence of a disturbance is seldom received. Through the operation described above, the influence of an instability factor of an accelerometer as described above can be reduced.